Generally, in the method of forming dye images by processing light-sensitive silver halide color photographic materials, the dye images are formed, after imagewise exposure, by reacting an oxidized p-phenylenediamine type color developing agent with a dye image-forming coupler. In such a method, a color reproduction method according to the subtractive color process is usually used to form dye images of cyan, magenta and yellow respectively corresponding to red, green and blue colors. Recent years, in the formation of such dye images, it is generally practiced to carry out a high temperature developing and simplify processing steps in order to achieve a shortened developing processing time. In particular, in order to achieve the shortened developing processing time, it becomes very important to increase the developing speed in color development. The developing speed in color development is governed from two approaches. One of them is a light-sensitive silver halide color photographic material, and the other of them is a color developing solution. In the former, the composition of the grains in a silver halide emulsion to be used may give great influence to the developing speed, and, in the latter, the conditions or composition of the color developing solution may give great influence to the developing speed.
Light-sensitive silver halide color photographic materials wherein a light-sensitive silver halide emulsion is substantially comprised of silver chloride (hereinafter referred to as light-sensitive silver chloride color photographic materials) can be rapidly developed as compared with conventional light-sensitive color photographic materials comprising a silver halide emulsion containing silver bromides or silver iodides such as silver chlorobromide, silver chloroiodobromide and silver iodobromide, and moreover can be free from accumulation in the color developing solution, of bromide ions or iodide ions which are susceptible to suppress development reactions. Thus, they are very useful as light-sensitive materials for a rapid processing. The present inventors have made various studies by using light-sensitive silver chloride color photographic materials suited for used in the rapid processing, and, as a result, find that the materials have the following disadvantages.
That is, as a first instance, hydroxylamine conventionally used as one of preservatives tends to act as a developing agent for the silver chloride so that the silver development may proceed, to lower color density of color images finally obtained.
As a second instance, sulfite conventionally used as other preservatives tends to act as a dissolving agent for the silver chloride so that the physical development due to a color developing agent may rapidly proceed, to lose the balance between the silver development reaction and the coupling reaction, in other words, the silver development may overly precede and the coupling reaction may delay, whereby the color density is lowered.
To solve the above first and second problems, the present inventors have made various studies. As a result, they have found that the above can be solved by using a particular compound as a preservative in place of the hydroxylamine and suppressing the sulfite to a concentration not more than a specific level whereby decrease in color density caused by the above problems, respectively, can be prevented well.
That is, the present inventors have combined the above two techniques, whereby it is made possible for the first time to obtain, at the first time, a light-sensitive silver halide color photographic material substantially comprised of silver chloride, being free from the decrease in color density and having good preservativity even with lower concentration of the sulfite in a color developing solution. As a result of further studies, it was also found that fog is liable to appear, especially when the solution is contaminated with a heavy metal ion.
This heavy ion may raise a problem especially when a large quantity of light-sensitive materials is continuously processed.
In a developing processing method of continuously processing light-sensitive silver halide color photographic materials by use of an automatic processor and the like, it is also necessary to take a measure for keeping components in a concentration in order to prevent the change in the development finishing performance due to the change in the concentration of the components. As such a measure, there has been usually used a method in which a replenishing solution is supplied to replenish short components and dilute unnecessary increased components. Supplying such a replenishing solution may bring about an overflow in a large quantity, which must be abandoned, throwing a great problem from an economical viewpoint and an environmental viewpoint. For this reason, in recent years, the so-called concentrated low replenishing system wherein the replenishing solution is made to have a higher concentration and supplies in a small quantity has been extensively used in order to decrease the above overflow solution. In such a system, however, heavy metal ions are liable to be accumulated, thereby raising the above problem of fog due to heavy metals. It has thus been sought after to solve these problems.
On the other hand, what is recently sought after in the present industrial fields is a technique that can practice rapid processing of a light-sensitive silver halide color photographic material, and yet can achieve good processing stability and stable photographic performances. Particularly sought after is a method of processing a light-sensitive silver halide color photographic material feasible for rapid processing.
More specifically, it is practiced to continuously process light-sensitive silver halide color photographic materials in an automatic processing machine installed in every photofinishing laboratory. However, as a part of improvements in services to users, it is demanded to finish processing and returns products to users in the day the development orders were received, and nowadays, it is further demanded even to return products in several hours after receipt of orders. Thus, a further progress is hastened for a technique that can carry out the processing more rapidly.
Further, in recent years, there is even a demand that an automatic processing machine is installed in the front of a camera shop or a supermarket, where light-sensitive materials received from users are processed on the spot and returned to them.
Also, a copying apparatus by which an original copy is irradiated with a light and copied on a light-sensitive material has also become commercially available, and it is also demanded in such an apparatus to develop in a short time the light-sensitive material on which the original copy has been copied. The state of affairs in such an apparatus is such that users are desirous of obtaining at once the copied light-sensitive materials.
For example, methods to enable rapid processing have been hitherto studied, and known methods include a method in which the processing is carried out by making high the temperature of a color developing solution, a method in which the pH of a color developing solution is kept in the high pH range, and a method in which development accelerator is used or a color developing agent is incorporated in a light-sensitive silver halide color photographic material. However, any of these methods mentioned above are involved in serious problems, and have not been put into practical use at present.
For example, in the instance the processing is carried out by making high the temperature of a color developing solution, the rapid processing is made possible to a certain degree, but there can be involved in the problems such that the oxidation decomposition of the developing solution itself may be greatly accelerated to cause a great compositional change of the developing solution, or the evaporation may take place so vigorously that the developing solution may suffer condensation seriously to make unstable the photographic performances. It can not necessarily be said that the oxidation decomposition of the developing solution have never occured at all in a conventional apparatus not designed for the rapid processing. However, they have occured only at a very low rate, not particularly resulting in any great damage on the photographic performances. These difficulties have been made extremely greater as a result of the high temperature processing, to cause serious problems in the photographic performances, for example, bring about hard gradation at the toe to make it impossible to achieve appropriate color reproduction. The method in which the pH range may have disadvantages that the photographic performances tend to vary and the stain tends to be generated since no agent is available that has buffering ability suited for maintaining the high pH.
In the instance a development accelerator is used, the development accelerator may include the compounds as disclosed in U.S. Pat. No. 2,950,970, No. 2,515,147, No. 2,496,903, No. 4,038,075 and No. 4,119,462; G.B. Pat. No. 1,430,998 and No. 1,455,413; Japanese Provisional Patent Publications No. 15831/1978, No. 62450/1980, No. 62451/1980, No. 62452/1980, No. 62453/1980, No. 12422/1981 and No. 62453/1980; Japanese Patent Publications No. 12422/1976 and No. 49728/1980; and the like. Among these, most frequently used in the so-called paper sensitive material in the light-sensitive silver halide color photographic material is benzyl alcohol that can exhibit good effect in accelerating the reaction of a color developing agent with an image-forming coupler.
However, the benzyl alcohol has problems that there is a limit in the amount for its use because of its poor solubility, and tar tends to be formed during its use over a long period of time.
As another technique for rapid processing, also known is a method in which a color developing agent is increased in a color developing solution to make greater the activity. This method, however, can not be put into practical use because the color developing agent is so expensive that the processing solution may be of comparatively high cost and at the same time there may be of comparatively high cost and at the same time there may be caused unstableness such that the developing agent is hardly soluble in water and readily deposits.
On the other hand, in order to achieve rapid processing of a color development by improving a light-sensitive material, there has been known a method in which the above-mentioned color developing agent is beforehand incorporated into a light-sensitive material. For example, there has been known a method in which a color developing agent is incorporated in the form of a metal salt (U.S. Pat. No. 3,719,492). This method, however, has had a disadvantage that the light-sensitive material shows poor storage properties when it is stored in a raw state, and therefore tends to be fogged before it is used or to be fogged at the time of color development.
In order to inactivate the amine moiety of the color developing agent, there has been also known a method in which the color developing agent is incorporated in the form of a Schiff base (U.S. Pat. No. 3,342,559; Research Disclosure No. 15159, 1976). This method, however, has had a disadvantage that color development can be initiated only after the color developing solution was hydrolyzed using an alkali, rather resulting in slow color development.
Further, in the instance the color developing agent is directly incorporated, there has also been a disadvantage that, in addition to the disadvantage that an emulsion may be fogged during storage because of unstableness of the color developing agent, various troubles on the processing may be caused because of weakened properties of an emulsion coating.
Thus, although it is possible to increase the development speed to a certain level when it is attempted to achieve the rapid processing with use of the above methods, there has greatly occurred compositional variation of a processing solution or deterioration of a processing solution, resulting in greatly harmful influence given to the photographic performances. Moreover, in the above methods, the color development speed can not be actually increased so much.
As a result of intensive studies, to enable sufficiently rapid processing, the present inventors have improved a light-sensitive material to find out that a silver chlorobromide emulsion or silver chloride emulsion containing silver chloride in a large amount may be used as the silver halide emulsion contained in said light-sensitivve material, and actually tried the rapid processing.
According to the present method, there is no change in the processing solution, and there may not be any great compositional variation or any extreme oxidation or evaporation of the processing solution. Moreover, there may not be caused the problem such as the storage properties in a raw state or the lowered color development efficiency as in the instance the color developing agent has been incorporated into a light-sensitive material, and thus it was made possible to carry out the rapid processing.
However, in the course of the studies the present inventors had proceeded, it was found that the emulsion containing rich silver chloride, though having good developing properties and being very suited for the rapid processing, has the problems as follows:
That is, although the sensitivity at the toe can be exhibited because of the good developing properties, the maximum color density tends to change to cause a great lowering of the density, and another problem is that the maximum color density tends to remarkably change particularly when the processing is carried out continuously.